configs/photon: Adds RGB led support

Approved-by: Gregory Nutt <gnutt@nuttx.org>

drivers/sensors: Adds support for INA3221 power sensor. This has a 3 channel bus/shunt voltage pairs.

Approved-by: Gregory Nutt <gnutt@nuttx.org>

drivers/rgbled: Adds support for multichannel PWM (multiple PWM channels on a single timer)

Approved-by: Gregory Nutt <gnutt@nuttx.org>

fs/nfs/rpc_clnt.c:  Commit 091e3f73 broke the NFS client.  sendto() can (correctly) no lnoger by used with a connected UDP socket.  In that case, send() must be used instead.

This commits adds initial support for the Kinetis Freedom-K28F board.  Not you ready for prime time.

Squashed commit of the following:

    arch/arm/src/kinetis:  A fixes from first (unsuccessful) attempt to build the Freedom-K28F configuration.
    configs/freedom-k28f:  Add basic board support for Freedom-K28F.  Initial commit is basically just the Teensy-3.x brought up to date and with name changes.

arch/arm/src/lpc17xx: This commit adds a configurable option to allow using a part of LPC17xx's internal flash memory as a Memory Technology Device via NuttX' mtd_progmem infrastructure. Tested with LPC1769.

configs/imxrt1050-evk:  This commit adds support for the imxrt button.  I haven't been able to get GPIO 5 to work so I have replaced the button with GPIO1 pin24. It is right next to the button so I just wire it to the existing user button for testing.

  imxrt_gpioirq.c
    - Add check for interrupt mask register before dispatching ISR. The GPIO_ISR bits are set independent of the GPIO_IMR bits.
  imxrt_irq.c
    - fixed a range check for extint in function imxrt_irqinfo().

Squashed commit of the following:

    arch/arm/src/kinetis:  Add K28F memory map.
    arch/arm/src/include/kinetis and src/kinetis:  Add basic chip features and interrupt-related definitions for the K28F

configs/nrf52-pca10040:  Fix an error in the name of an included file.  This was introduced with the previous change to this file.

progmem interface: Discern r/w and erase page sizes.  Introduce new up_progmem_erasesize architecture API to be able to communicate the read/write page size independently from erase page size.  Implement up_progmem_erasesize for all architectures that already support progmem, assuming that for those architectures the sizes of both read/write and erase pages are identical.

arch/arm/src/nrf52:  Fix several inconsistencies in naming.  Mostly cosmetic but one was causing a compiler warning.

include/nuttx/wireless/bluetooth:  Move Bluetooth header files from include/nuttx/wireless to include/nuttx/wireless/bluetooth for symmetry with other wireless technologies.

arch/arm/src/tiva:  Implemented Flash CONFIG_MTD_BYTE_WRITE for TM4c1294.  Implemented the tiva_write function which will write an arbitrary number of bytes to flash (in multiple of 4).

arch/arm/src/tiva:  Implements an EEPROM driver in compliance with MTD driver as provided by NUTTX for TM4C1294.  The EEPROM driver currently supports only two functionalities - read bytes(multiple of 4) and write bytes (multiple of 4).

Squashed commit of the following:

Author: Gregory Nutt <gnutt@nuttx.org>
    Fix some spacing
    arch/arm/src/tiva:  Verify that the EEPROM driver at least builds.
    arch/arm/src/tiva:  Move unused function added to tm4c129_syscontrol.c to tiva_eeprom.c where it is actually used.
    arch/arm/src/tiva:  Reorganize EEPROM register definitions so that the file organization is more like other platforms.
    arch/arm/src/tiva:  Trying to resolve EEPROM register addressing.  Still some issues.
    arch/arm/src/tiva:  Ran uncrustify on tiva_eeprom.c
    arch/arm/src/tiva:  EEPROM driver is a little closer to coding standard.  Still a way to go.

Author: Shirshak Sengupta <sgshirshak@gmail.com>
    arch/arm/src/tiva: Implemented EEPROM driver in compliance with MTD driver as provided by NUTTX for TM4C1294. The EEPROM driver needs to be initialized by calling the function tiva_EEPROMInit The EEPROM driver currently supports only two functionalities - read bytes(multiple of 4) and write bytes (multiple of 4). Note - Rest of the features of EEPROM will be implemented in the future.

Makefile.unix:  There is a sort command in the 'make savedefconfig' file.  I found that sort behaves differently on different platforms based on the environment variable LC_ALL.  Now, Makefile.unix will force LC_ALL=C just for the sort command so that we can all generate equivalent defconfig files.

kinetis usb device fixes

* kinetis:usb device use correct CONFIG OTG control

* kinetis:usb device fix interrupt storm when cable is disconnected

      The DM, DP state were incorrect because the pulldowns were not
      enabled.

      Also the pending asynchronous resume interrupt needed to be
      re-armed after the suspend is in effect. This is now done in
      the isr.

Approved-by: Gregory Nutt <gnutt@nuttx.org>

fs/vfs and net/udp:  Repartition logic of commit 0c963449, moving into net/udp.  Add support to handle connected UDP sockets.  The correct 'optimal blksize' to return is the MSS.  The MTU is always too big.

net/udp:  Correct an error introduce in recent fixes for UDP connected sockets.  The interaction between psock_udp_send() and psock_udp_sendto() was perverse:  It should always pass a NULL destinatino address.